Question: Simplify the following expression: $x = \dfrac{3}{8a} + \dfrac{1}{5a}$
Solution: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $8a$ and $5a$ $\lcm(8a, 5a) = 40a$ $ x = \dfrac{5}{5} \cdot \dfrac{3}{8a} + \dfrac{8}{8} \cdot \dfrac{1}{5a} $ $x = \dfrac{15}{40a} + \dfrac{8}{40a}$ $x = \dfrac{15 +8}{40a}$ $x = \dfrac{23}{40a}$